A Royal College of Art student has designed a plant-based water filtration system that is capable of cleansing home wastewater whilst growing herbs at the same time. Pratik Ghosh’s “Drop by Drop” filters water in a way similar to the natural transpiration process that occurs in the Amazon rainforest. Simply put, it is a mini biosphere that operates by keeping humidity, light and heat (the factors crucial for transpiration) at optimal levels. Ghosh explains that “the system pulls moisture out of the air and condenses it into pure distilled water.”
Drop by Drop covers a plant with a glass dome and grey water (dirty water from the kitchen and bathroom sinks) is added via pipes. A light sets off photosynthesis, and the plant gives off water vapour that can ultimately be condensed into distilled water. Adding minerals can turn the distilled water into drinking water. If you use a plant that is a natural herb you get the extra benefit of growing something that is healthy and organic. Drop by Drop requires very little maintenance, and it is capable of becoming a self-sustaining biosphere. The microbes and insects in the soil provide carbon dioxide for the photosynthesis, and the system releases extra oxygen into the surrounding air.
The small prototype takes 12 hours to filter one glass of water, but the system has the potential to be scaled up to cover the entire rooftop of a home. At that size it could then filter around 160 litres in 12 hours. Water is a commodity that many people take for granted, though here on Ibiza we are aware of its value and its scarcity. As Ghosh points out, “There needs to be a change in how we care for water, and what better place to start than in the home.”